Air-conditioning apparatus; Air-conditioning installations; Air filtering installations; Air humidifiers; Air purifying apparatus and machines; Gas scrubbing apparatus; Ionization apparatus for the treatment of air; Ionization apparatus for the treatment of water; Purification installations for sewage; Water purification installations

Air analysis apparatus; Air quality measurement apparatus, namely, particle counters; Data processing apparatus; Depth gauges; Electric sensors; Electric, electronic, or electrochemical oxygen monitors and sensors for environmental use; Electro-dynamic apparatus for the remote control of signals; Gas testing instruments; Measuring apparatus, namely, angle finders; Optical sensors; Remote control telemetering apparatus; Sensors for the determination of temperatures, positions and distances; Sm...